Electric-lamp socket



March 17, 1925.

I M. J. GRETSCH I ELECTRIC'LAMP SOCKET Filed Sept. 20. 1919 2 Sheets-Sheet 1 March 17, 1925.

M. J. GRETSCH ELECTRIC LAMP SOCKET Filed Sept. 20. 1919 2 Sheets-Sheet 2 Patented Mar. 17, 1925.

UNITED STATES MARK a". onnrson, or new YORK. n. A

MnNTs. or ONE-HALF TO vane. onscreen BOTH OF NEW YORK, N. Y.

SSIGNOR BY DIRECT AND MESNE ASSIGN- All'?) GEE-HALF TO SADIE SURTSHIN,

ELECTRIC-LAMP SOCKET.

Application filed September 20, 1919. Serial No. 325,170.

To all whom it may concern:

Be it known that I, MARK J. Gnn'rsoir. a citizen oi the United States. residing at New York, in the county of New York and State of New York, have invented certain new and useful Improvements in Electric- Lamp Sockets of which the following is a specification.

The present invention has reference to electric sockets i. e. sockets for incandescent lights or bulbs in which the circuit to and from the light is controlled by a chain operated mechanism so that by one pull oi the chain the circuit becomes closed and by the next pull the same is brolren and the light extinguished.

The invention is an improvement over the one described, shown and. claimed in my earlier Patent #LQQ LJM. The construction according to said patent has been found impracticable and not durable by reason of the shaft which carries the commutator being made wabbling. Furthermore the confinement of the parts of the mechanism in an entirely closed casing renders the parts inaccessible for insertion, exchange and repair thereof. 7 j

My present improvement removes these drawbacks and moreoverconsiderably simplifies the construction of the socket and renders it durable.

in the accompanying drawing in which similar reference characters denote corresponding parts, Fig. 1 is a side elevation of the pull socket with the shells of the casing removed; Fig.2 is a similarview at a right angle to that of Fig. 1 and with a part of the insulation body supporting part of the operating mechanism shown in section; Fig. 3 is an inner plan view of the said insulation body; Fig. 4 is a plan view of another section of the insulation bodycarrying the socket terminals; Fig. 5 is an outer partial plan view of said last named section; 6 is a vertical section of the same insulation section; Fig. '7 is a side elevation showing the commutator and the plunger cooperating therewith; Fig. 8 shows the chain operated crank arm and ratchet in two elevations at right angles to one another; Fig. 9 is an elevation of the arbor, crank arm and commutator with an insulation guard shown in sec-' tion; Fig. 10 shows aperspective View of the insulation guard; Fig.11 is a similar view of a modified guard; Fig. 12 shows two elevations at right angles to one another of a part of the mechanismcooperatingwith the commutator; Fig. 13 is a vertical section otthe same part shown in Fig. '6 somewhat modified; Fig. 1% is a perspective view of the plunger forming part of said 'mecha nism; Fig. 15 is a perspective view of a part of the socket in which the said plunger moves, Fig. 16 is a side elevation of the crank arm somewhat modified in construction; and Fig. 17 is a vertical section through the insulation body at a right angle to the view shown in Fig. 2. p 1

Referring specifically to the drawing, 22 denotes the roll threaded sleeve inwhich the incandescent electric lamp (not shown) is adapted to be screwed. The body supporting the operating mechanism to be described hereinafter is composed of two sections 18 and 1 of insulation material, such as porcelain or the like. The two sections are arranged above and at a certain elevation from one another to form an open space (i between themselves, which affords access to the parts of the operating mechanism. The sections 1 and 18 are connected to and sup ported on one another by two brackets 2 and 3 whose ends 2 2 and 3 3 are bent at a right angle to themselves and have threaded bores for screw bolts 25, b, a 0, whereby they are fixed to said sections 1 and 18 and the socket 22; the screw bolt c 01 the bracket 2 holding the socket 22 being suitably insulated from the latter. I I

T is section 1 is a substantially cylindrical body of comparative thickness formed in its inner face with a diametrically extending groove 1 open at its ends. One of the walls of said groove is centrally cut out to form a substantially square cross groove 1 which in width conforms with the breadth of the bracket 2 so that the latter will snugly lit therein with its end 2 resting against the bottom 1 of said groove. has a central shallow cylindrical groove 1 to form a'bearing for one end of the arbor 4e of the chain operated commutator to be presently described. This wall also has a lateral groove 1 the breadth of the bracket 3 so that the latter will snugly fit therein with its bent end The opposite wall I conforming in width with i fill 3 resting against the bottom 1" of said groove. The bracket 2 has a central bore 2* which serves as a bearing for the other end of the arbor 4. Leading into the cavi ties or grooves 1 1 from the outer face of the body are perforations through which the bolts 6 are passed which work in the threaded bores of the ends 2 3 of the brackets 2 and 3. The brackets 2 and 3 each also carry a. terminal screw (Z for the attachment of the electric wires (not shown).

The arbor l is thus supported at one end in the cylindrical groove 1 of the body 1 and at its opposite end in the hole 2 of the bracket 2 and at this latter end is adapted to be conductively connectedwith the terminal d borne in said bracket 2, but insulated from the socket 522 by the insulation (not shown) of the screw 0.

Rotathxely and centrally borne on this arbor l is a disk in form of a toothed wheel made of fibre or other approved insulation material. This body is sheathed with a metal covering 11 arranged at one side thereof as best shown in Figs. 9 and 10, and having extensions 11 covering two opposite teeth, while the other two ofthe four teeth remain uncovered. The two metal covered teeth are adapted "to transmit current, while the unsheathed teeth of insulationmaterial remain non-conductive. The metal coverin ll of'the commutator cooperates with the tooth shaped projections 9 formed on a metal ratchet shaped disc S fixed to a crank arm 6 made of suitable insulation material. The arm 6 is rotatively borne with its hub portion on the arbor 4 so that the ratchet 8 is opposite and in contact with thespoke shaped parts out metal covering 11 oi the commutator (F 9). The holding of the ratchet constantly in contact with the commutator is effected by a spiral spring 5 mounted around the arbor l and of which one end engages a hole in the arm Gand the other may be engaged with any one .of a set of prongs formed onthe bracket 2 (FigyQ). The object of the set of prongs 2" is to permit adjustment. of the tension of the spring when necessary.

At the extreme free end of the arm (3 i provide a hook shapedmember 7 formed with a. notch 7" extending longitudinally in the curved portion (Fig. 8) which serves for the engagement of the pull chain 112 which is of the usual characteristic structure used with the devices.

Mounted on the arbor {l is a guard in shape of a mud-guard, which serves the purpose of preventing the chain 12 from coming into contact with the metal part oi the commutator and from thus accidentally closing the circuit. This guard may have i a back l3 having a central perforation 13 95 for its support on the arbor 4 or the guard may be in form of a semicircular band 13 the ends of which are bent horizontally andperforated (Fig. 11) to allow its being screwed to the inner face of the section 18 of the insulation body.

lVhen the parts are properly assembled the arbor 4 will extend across the groove 1 the insulation section 1, with" its ends resting on one side in the cylindrical bore 1" and on the other side in the perforation 2 of the bracket The commutator 10. 11, ratchet 8, arm (3 and guard 13, or 13 will be located just above and partly projecting into the groove 1 of the insulation body 1.

Owing to the action of the spring 5 the ratchetwill be in contact with the metal side of the commutator and in cooperation with the teeth thereof produce a step by step rotary motion of the conunutator when the chain is pulled downwardly.

The section 18 of the insulation body which supports another part of the circuit make and break mechanism to be presently described may be in the form of a diskhaving a central cavity 18 and a substantially U-shaped opening 155 in its inner face (Fig. 6) The cavity serves to accommodate in itself a contact piece composed of two metal members slidably engaging one another and adapted to come in direct contact with the center of the electric lamp when inserted into the threaded sleeve 22. According to the construction shown in Figs. 5 and 6 one of the metal members is a stationary piece of metal 16 bent in form of a U-litting in the cavity 18 and provided centrally with a finger or part 20 projecting outwardly from the cavity to form a contacton which the metal base of the electric bulb will rest. Slidably supported between the vertical walls of the member 16 is a plunger ll. The latter is made of a metal piece bent upon itself to form a U- haped frame adapted to loosely bear in the opening 18 of the section 18, and to project outwardly therefrom in the downward direction. The upper parts lt and lt of said frame are bent horizontally andadapted to lie in the cavity 18, the said parts being extended so that their free ends are in contact with or slidably bear on the vertical walls of the stationary member 16. The U-shaped part of the metal frame 14 is reinforcedlby a forked or U-shaped block or member 1501" insulat ing material. This member is mounted between the walls of the U-shaped parts oi the metal frame 14 and its forks project outwardly therefrom at the sides of the frame 14L (Figs. 2 and 7) and are extendedrearwardly (Figs. 5 and l t). The bottom of said frame is adapted to bear on the commutator wheel 10 and to be held continuously in contact therewith by a spring 17 mounted in the cavity 18' and bearing at its.

upper end against the stationary member 16, and at its lower end against the horizontal parts 14, 14 of the frame 1-1. As the commutator wheel revolves, the bottom of the member 14 will slide over the sheathed and unsheathed teeth thereof, an d alternately close and break the circuit. lhe rearwardly extended parts of the block 15 will insulate the walls of the U-shaped metal frame 1% from the metal coverings 11 and at the same time in abutting against the shoulders formed by the ratchet tooth of the wheel 10 act as stop preventing retrograde move- .ment of the commutator. The fork shaped insulating block 15 will, in projecting through the opening 18 of section 18, also act as guides for the member or plunger 1 In Fig. 12 the movable contact piece in the insulation section 18 consists of a metal frame or member 16 which is adapted to fit in the cavity 18 and which is formed with a curved yoke-shaped projection. is adapted to project into the socket 22 to form a contact for the electric bulb. One of the walls of said member is extended and bent inwardly as at 2' and the opposite wall has a groove or slot j. The plunger consists of a metal frame 14 arranged in said frame .16 to extend crosswise thereto and contains a piece of fibre 15 or other suitable body. The lateral Wall of said second frame has a slot 7:; for engaging the bent extension 2' of the frame 16 and the free end at of the inner wall of said frame l i is extended and adapted to engage the groove or slot j in the member 16. By these means the member lt is guided vertically during its movement when acted upon by the commutator.

Instead of a single member 16, two separate metal pieces 16 may be provided each having its outer end bent at a right angle. In this case the spring 17 will be mounted between the insulation plate 19 and the plunger 1e, 15 and screw bolts a holding the insulation plate in position Will pass through perforations in the bent ends of the pieces 16 (Figs. 13 and 15). The screw bolts 72 may be directly connected with the roll threaded shell 22 so that the circuit in this *ase will flow to the sides of the electric lamp, while the bulb is supplied in the usual way by extending the bracket 9 (corresponding to bracket 3 of Fig. 2) to meet the centre of the bulb and avoiding contact with the shell 22 (Fig. 13).

To allow of the chain being easily and conveniently hooked to the crank arm-the hook Z may be provided with an L-shaped cross slit 0 (Fig. 16) instead of with the longitudinal slit 7 shown in Fig. 8. By such arrangement the chain can be slipped into the slit 0 from the back without the necessity of using any tool, as seen from Fig. 17.

By virtue of the arrangement of the insulation body 1, 18, in two separate sections with a free space between them easy access can be had to the operating parts and when some of the parts, as for instance the pull chain or the spring 5 becomes disconnected, which is a frequent occurrence, it will not require the taking apart of the socket, excepting the removal of the outer shells.

Another advantage of my new socket is that it afl'ords a saving of material and a considerable reduction of weight.

Another novel feature of my new socket lies in the construction of the ratchet wheel f). is seen from Figure the ratchet wheel 8 consists of a comparatively thin circular plate having peripheral projections 8 which are adapted to be passed through slots 6 in the crank arm 6, and then folded over the back of the latter, thereby securing said plate in position. The tooth or teeth 9 of said plates are formed by peripheral projections which are folded upon themselves to form shoulders 9 which act as ratchet teeth. A wheel of such con struction has proved to be more durable than those of the hitherto used ratchet wheels.

What I claim and Letters Patent is:

A lamp socket having an. insulation body composed of two superimposed but separate: sections forming an open space between themselves, a commutator rotatively bornev in one of said sections and a circuit make and break mechanism in the opposite section comprising a vertically movable plunger cooperating with said commutator and having an insulated portion to act as a stop, preventing retrograde movement of said commutator.

2. A. lamp socket having an insulation body composed of two superimposed but separate sections forming an open space between themselves, a commutator rotatively borne in one of said sections and a circuit make and break mechanism in the opposite section comprising a vertically movable plunger formed with a projection of insulation material and cooperating with said desire to secure by commutator to close and break the circuit,

said projection serving as a stop to prevent retrograde movement of the commutator.

8. A lamp socket having an insulation body composed of two sections superimposed but separate from one another to form a free space between themselves, an. arbor supported in one of said sections, a. rotary ratchet shaped comntutator and a crank arm for imparting step by step movementto said commutator, said commutator and arm being loosely borne on said arbor, and a circuit the opposite section comprising avertically movable plunger adapted to cooperate with said commutator to close and break the cirmake and break mechanism in cuit and having an insulated portion to art as a stop, preventingretrograde movement of said commutator.

4-. In an electric lamp socket, a rotary commutator of insulation material having ratchet shaped teeth. a metal sheath at one side of said commutator having extensions covering some of the teeth of said commutator a make and break mechanism comprising a stationary metal part having means to form contact with the center of the lamp, a spring actuated metal plunger bearing; in said stationary member and the bottom of which is adapted to be constantly in contact with said commutator, and an insulation body carried by said plunger and adapted to insulate the walls of said plunger against the metal sheath and to act as a stop preventing retrograde movement of the said commutator.

In testimony whereoit I aflix my signa ture in presenceot two witnesses.

MARK J. GRETSCH. Vitnesses:

MAX D. O DMANX, IRMA MAL'roN. 

